What causes 'bad sectors' on a hard drive?

Hi I’ve 23 WH Caviar Black hard drives (mostly 2Tb), 10 of them permanently attached to my system (in ventilated enclosures), for the rest I use a docking station. Recently 2 of them have completely failed and a third is reporting bad sectors (all of them the 2Tb variety and permanently mounted). My PC runs 24/7. I have a Gigabyte EX58 mainboard, a BFG 1200W power supply and the entire PC is protected by a Powerware UPS.

My question is: What causes bad sectors? I know everything will eventually fail, but my drives are less than 2.5 years old. I take what I consider to be good care of them - they are not subjected to moisture, vibration, knocks or bumps. They are not allowed to overheat, they have good, clean and sufficient power supplied to them. I clean the inside of my PC case of dust about twice a year. The cables are of good quality, as is the rest of my PC. They are defragged every couple of weeks and checked for errors once every 2 or 3 months. But in spite of this, drives that are guaranteed for 5 years are failing before half of that time has passed.

What could be causing them to develop bad sectors and eventually fail? I can (possibly) understand 1 out of 23 (just over 4%) - but THREE??? That’s over 13% failure rate!! Unacceptable!!

There are several causes of bad sectors on hard drives. Bad sectors may be a result of regular everyday use for a substantial amount of time. The problem of damaged sectors can also be present in new out-of-the-box hard disks. Physical damage or shock can even lead the hard drive to have bad sectors. If the hard disk experiences a strong jerk, the platter can be damaged, which might in turn create bad sectors. Another reason for damaged sectors is excessive generation of heat in the PC and improper ventilation settings.

Thanks very much for the reply!

Your answer was VERY vague. Could you please be a little more descriptive and / or specific? For example:

-‘Regular everyday use’ - used for what? Under which circumstances? In what kind of system - office? Home? Gaming? Server?

-‘Substantial amount of time’ - how much time? Measured in what - weeks? Months? Years? Decades?

Why exactly could bad sectors be present in even brand-new out-of-the-box drives?

What exactly is a ‘strong jerk’? I have absolutely no idea what this might mean.

I understand that physical damage, shocks and excessive heat (how hot, exactly - what temperature?) can damage a drive and / or cause bad sectors. But the main thing I want to know is the reasons for the bad sectors on *MY* hard drives - which are not subjected to physical damage, shocks or excessive heat.

My computer sits in the floor. It is not picked up. It is not dropped - it is not even moved. It is not subjected to shocks of any kind. It is not damaged. The drives are kept more or less at room temperature - all the time. The drives are in a properly ventilated and fanned enclosure. The drives are not very old. And I specifically bought the higher-performance drives so that I wouldn’t have to worry about problems like this - I deliberately paid the higher price for these exact drives, but I’m NOT seeing the benefits.

They are still developing bad sectors and failing before they reach the end of their advertised life-span - and I want to understand the reasons for this.

hello my friend… sorry but that user anwser was not vague…  Regular everyday use is for example writing and reading a lot of  data from the hard drive…

the substancial amount of time  is hours for example 10-12 hours or turned on 24h for a day

Our drives could die at any moment… is only developing bad sectors so you can recover the data

what i think is that the probability of developing bad sectors is higher when more bytes are crunched in the platter

so normaly old hard drives are better at this porpose but lacks storage capacity lol

See if this helps.  I found them doing a google search.





I posted this a while ago http://community.wdc.com/t5/Off-Topic-Discussions/How-Hard-Drives-Work/m-p/321293#M621 the videos explain how drives works and explains a bit about bad sectors also.



Hello there

Thanks for the links (which I have read). Unfortunately they did not tell me anything I didn’t already know; what I would like to understand is the cause of bad sectors on MY hard drives. I have had two drives fail in quick succession (and a third in the process of failing) WAY sooner than they should have. I want to understand the reasons why - it is possible *I’M* doing something wrong (however, I think this is VERY unlikely!), and I want to correct this ASAP if this is the case. If it’s not my fault, then I want to know why the drives are failing before their time.

But thankyou anyway.

Well sorry to say :

Utter rubbish hard drive i will never support it again because they do not honor their warranty. I have owned 640 GB 2.5" & 1 TB 2.5" and looked after them properly but they ended up having bad sectors. I bought my drives from 2 different locations of the world,USA & Philippines.Both looked after very well, but i ended up having issues with Cyclic Redundancy Check.Lifeguard Tools reported bad sectors and it suggested that it may be able to fix the errors but it was unsuccessful. sorry its junk.

I just can not explain how frsutrated i am being passed along to phone other distributers here and they can not help me because i bought it over seas. its really ridiculous and i gave Western Diginal Elements a second chance which has caused me more pain.

If Western Digital can not help me then i am not prepared to support the brand and i will do the right thing and not recommened i

any drive gets bad sectors eventually.